Abstract: A creping doctor (2) for creping a soft paper web (3) off a yankee cylinder (1) is described which comprises a supporting beam (4) disposed close to the envelope surface of the yankee cylinder (1) and provided with an internal space, the internal space being divided into a first longitudinal suction chamber (24) and a second longitudinal suction chamber (25). The creping doctor also produces a subatmospheric pressure in the suction chambers (24, 25); a first suction connection (18, 19, 21) connecting the first suction chamber (24) of the supporting beam (4) to an external dust-generating space (7) located between the doctor blade (6) and the soft paper web (3) creped off; and a second suction connection (40, 42, 43) connecting the second suction chamber (25) of the supporting beam (4) with an internal dust-generating space (8) located between the doctor blade (6) and the envelope surface of the yankee cylinder (1).
Type:
Grant
Filed:
February 28, 1990
Date of Patent:
April 30, 1991
Assignee:
Valmet Paper Machinery, Inc.
Inventors:
Tord G. Gustavsson, Harry I. Myren, Karl T. I. Silja
Abstract: A creping doctor (2) for creping a soft paper web (3) off a yankee cylinder (1) is described which comprises a supporting beam (4) disposed close to the envelope surface of the yankee cylinder (1) and provided with an internal space, the internal space of the supporting beam (4) is divided into a first longitudinal suction chamber (24) and a second longitudinal suction chamber (25). The creping doctor also produces a subatmospheric pressure in the suction chambers (24, 25); a first suction connection (18, 19, 21) connecting the first suction chamber (24) of the supporting beam (4) to an external dust-generating space (7) located between the doctor blade (6) and the soft paper web (3) creped off; and a second suction connection (40, 42, 43) connecting the second suction chamber (25) of the supporting beam (4) with an internal dust-generating space (8) located between the doctor blade (6) and the envelope surface of the yankee cylinder (1).
Type:
Grant
Filed:
February 28, 1990
Date of Patent:
April 16, 1991
Assignee:
Valmet Paper Machinery, Inc.
Inventors:
Tord G. Gustavsson, Frans O. S. Lyxell, Karl T. I. Silja
Abstract: A method of and an arrangement for leading a web on to a desired wire in a paper machine or the like. When the web moves between two wires, it is transferred on to one wire after the wires have moved in parallel over a distance with the web therebetween making contact with both wires. The transfer takes place when the wires start to move in different directions by sucking the web on to one of the wires by a vacuum acting through said wire. For improving the detachment of the web from the other wire, the direction of travel of the wire is changed abruptly at the parting point of the wires by leading it along a suction box comprising a cover piece formed by cleats and arranged to form an angle in such a way that the point of the angle projects towards the wire. When the wire moves along the cleats of the cover piece of the suction box, its direction of travel is abruptly changed at the point line of the angle, whereby the web is detached from the other wire completely in a moment.
Type:
Grant
Filed:
June 13, 1988
Date of Patent:
October 23, 1990
Assignee:
Oy Tampella AB
Inventors:
Veikko Lamminen, Erkki Hietikko, Ilpo Kylmakorpi
Abstract: The suction box cover able to support a stock wire (31) over it, the stock wire running as in the prior art of paper mill machinery, the suction box cover 10 having a frame structure constructed by external side member 11,111 and a plurality of blades 13, 14, 15, intermediate, front and back, including a carrier 18 and running blades 19 connected together, the blades 13, 14, 15 being the running table of the wire and being supported by a plurality of profiled or shaped staffs oriented orthogonally to the blades and connected to the external side members 11, 111. The suction box cover is closed at the sides by removable seals 29, and the suction box cover is connectable by means of the side members to a lower suction box 26.
Abstract: A layer of particulate material is formed by forming a foamed dispersion of a particulate material, supplying the foamed dispersion to a predetermined zone of a plane through which a foraminous element is moving, applying a vacuum to said plane across the zone on the other side of the foraminous element, so as to drain foam and form a particulate layer thereon, removing any free air from the drained foam, and continuously recycling the resulting foam for re-use in forming the foamed particulate dispersion. An apparatus is provided for carrying out the process.
Abstract: An improved suction box for paper making machine includes a cover for contacting a press fabric with an elongated slot. The slot is covered with a mesh to eliminate noise and reduce wear on the fabric.
Abstract: A joint dewatering zone of wires for dewatering a web to be formed in a two-wire papermachine having a first wire loop and a second wire loop, includes a first forming roll which is situated inside the second wire loop and other dewatering means which are situated after the first forming roll inside the first wire loop. The other dewatering means comprises as a combination a first suction box, a second suction box with a curved guiding surface, and a roll interposed between the suction boxes.
Abstract: In a tissue paper machine, the dust that is released when the web is creped off the Yankee dryer (3) constitutes a major work environment problem. To provide an improved extraction of the dust and thereby improve the work environment for the operating personnel involved, a dust extractor (25") having an internal space (39") and a web stabilizing, imperforate plane (37") is mounted immediately adjacent to an intended path of travel for the creped web (1) so that the web during its transportation will place itself in a fixed position close to the imperforate plane (37"), and, at least an essential part of an entrained boundary layer of dust containing air is eliminated through suction only, to the internal space (39"). The suction is carried out at the rear and/or front edge of the extractor (25), and suitably both on the overside and underside of the web (1).
Abstract: A bulky, embossed, fibrous web material having a basis weight in the range of 5 to 50 lbs./ream and geometric means tensile strength (TS) (kg/3" width), apparent bulk (AB) (cal. pts./lb. ream), and oil holding capacity (OH) (ml/gm fiber) substantially satisfying, in absolute values, the relationships (0.27 BW-1) TS>(0.17 BW-1), AB>[0.7-(TS.div.20)], and OH 0.063TS.sup.2 -1.13TS+8.6. The invention includes an apparatus and a method of manufacturing the product comprising wet pressing a fibrous web to about 30% to 50% solids, conveying the web to a transfer position proximate the three-dimensional surface of an embossing fabric moving at a speed less than that of the web at the transfer position, and applying a vacuum to the web through the embossing fabric to transfer and conform the web to the three-dimensional surface of the fabric, the vacuum magnitude being in the range of 1 to 20 inches Hg.
Abstract: A sheet of fibrous web material having opposite smooth surfaces, an apparent bulk in the range of about 0.10 to about 0.20 caliper pts/lb ream and a machine direction stretch of at least 8%, wherein surface undulations on the opposite smooth surfaces of the sheet have an amplitude variance of less than 0.0002 inch. The invention includes an apparatus and a method of manufacturing the product comprising partially dewatering a wet fibrous web to about 30% to 50% solids, conveying the web to a compression nip defined by a smooth-surfaced roll and a smooth-surfaced fabric material, moving the fabric material at a speed of about 10% to 20% less than the surface speed of the smooth-surfaced roll, compressing the web in the nip with a compression force of less than 15 lbs/linear inch, with an average pressure of less than about 50 psi in the compression nip, and drying the web. The dried web has an apparent bulk less than 0.20 caliper pts/lb ream.
Abstract: A method and apparatus are provided for the adjustment of the dewatering in the wire section of a paper machine. A fiber web is fed on to a forming wire, and the forming wire is passed over the surface of at least one dewatering means and a partial vacuum dependent on the difference in the speeds of the wire and said surface is created under the forming wire. An additional movable wire is positioned to move between the forming wire and the dewatering means and the dewatering is adjusted according to the kind of the fibre web to be dewatered, by adjusting the speed of the additional wire independently of the speed of the forming wire.
Abstract: A suction transfer device located over a length of a single continuous dryer fabric extending between two rolls and below which length the web to be dried extends, with the device producing preferential negative pressure in active sections at the edges of the fabric with relation to a relatively inactive central section between said active sections.
Abstract: A suction box coordinated with a dandy roll and serving the dehydration of paper webs features on its ends respective deckle slides wherein each deckle slide is of a design such that it elastically yields to the peripheral face of the dandy roll. Each deckle slide is wear-resistant and adaptable to varying dandy roll diameters and dipping depths. Thus, each deckle slide comprises a lamella package which extends with its longitudinal axis in the direction of web travel. The lamella package includes a plurality of parallel, rigid lamellae shiftable relative to one another and lying in respective planes extending generally perpendicular to the direction of web travel.
Abstract: A twin wire papermaking machine which has a multichambered suction dewatering device located over the forming wires downstream from the forming roll. The dewatering device deflects the forming wires into a concave path to aid in formation and dewatering.
Type:
Grant
Filed:
September 28, 1981
Date of Patent:
November 8, 1983
Assignees:
Australian Paper Manufacturers Limited, Beloit Corporation
Abstract: A procedure for dewatering and detaching a paper web from the second former wire. The composite of first and second wire and interposed web is contacted with a first cover part of a special suction box. A roll guiding the second wire, pressing from the side of the latter deflects its run. This pressure plus centrifugal force, and the differential pressure arising from the suction box, dewater the web. The second wire is separated to follow along with the guide roll, while web and first wire are acted on by the suction box vacuum. The first wire is then contacted with a second cover part of the suction box. A twin-wire former is also disclosed, featuring within its carrying wire loop, on its twin-wire run, a rotating forming roll deflecting the composite of wires and web as it laps a given sector of said forming roll. A special suction box at the ultimate end of the wires has a bipartite cover its parts angulated against each other and preferably planar.
Abstract: An apparatus for transporting a sheet of a flexible material between a first and a second position. The apparatus includes an elongated frame and an air-pervious endless belt movably mounted on first and second pulleys positioned at each end of the frame. The belt has its upper rung travelling from the first pulley, adjacent the first position, to the second pulley, adjacent the second position, and is arranged to receive a lead strip of the sheet from the first position. A vacuum chest having a perforated top extends longitudinally of and below the upper rung of the belt. There are means for evacuating air from the chest in order to apply a vacuum at the undersurface of the belt and thereby cause the lead strip to cling to the belt. The apparatus has means defining an opening where the sheet leaves the belt and an air jet means able to direct air through the opening.
Abstract: A suction pipe for a paper machine having a tapered seat and a cover and an insert mounted in the seat to provide an air tight seal therewith. The insert and the cover being laterally removable from the seat after sufficient longitudinal travel of the cover to free the insert in the seat.